Recording apparatus



April 22, 1941.

H. e. JOHNSTONE arm. 2,239,524

RECORDING APPARATUS Original Filed Aug. 28, 192 8 10 Sheets-Sheet 1 P? 1941- H. G. JOHNSTONE ETAL 2,239,524

RECORDING APPARATUS Original Filed Aug. 28, 1928 10 Sheets-Sheet 2 -10 Sheets-Sheet 3 RECORDING APPARATUS H. G. JOHNSTONE ETAL Original Filed Aug. 28, 1928 April 22, 194-1.

awn Mi Hake/a 6 Johns/0m! Warm Ap 1941- H. G. JOHNSTONE ETIAL 2,239,524

RECORDING APPARATUS 1 0 Sheets-Sheet 4 Original Filed Aug. 28, 1928 Ii! milliilllll] Illln||||||||||||||||||| April 22, 1941.

RECORDING APPARATUS Original Filed Aug. 2a, 1928 10 Sheet-Sheet 5 April 1941- H. G. JOHNSTONE ETAL 2,239,524

RECORDING APPARATUS Original Filed Aug. 28, 1928 l0 Sheets-Sheet 6 fig 227 HOURS RATE DEPT. TOTAL COST O O O O I 2 3 4 5 6 7 8 9 l0 l2 l3 2.9303/323334853673839 4040124344245 Wye/7f; flaw/d 6. Jab/75m Wows/7 A. 0774/ H. G. JOHNSTONE ETAL 2,239,524

April 22, 1941.

RECORDING APPARATUS Original Filed Aug. 28, 1928 I0 Sheets-Sheet '7 M w Z im w 5% m W6.

April 1941- I. H. G. JOHNSTONE ETAL 2,239,524

RECORDING APPARATLZS Original Filed Aug. 28, 1928 10 Sheets-Sheet 8 April 22, 9 1- H. s. JOHNSTONE ETAL 2,239,524

RECORDING APPARATUS Original Filed Aug. 28, 1928 10 Sheets-Sheet 9 April 22, 1941. H. G. JOHNSTONE EI'AL RECORDING AP PARATU 5 Original Filed Aug. 28, 1928 10 Sheets-Sheet 10 5' /3 fly /4 Patented Apr. 22, 1941 Harold Glenn Johnstone, Oak Park, and Norbert Karl Engst, Berwyn, 111., assignors to Western Electric Company, Incorporated, New York,

N. Y., a corporation of New York Original application August 28, 1928, Serial No. 302,463. Divided and this application February 6, 1929, Serial No. 337,851

(or. ass-61.10)

24 Claims.

This invention relates to recording apparatus, and more particularly to perforating apparatus for use in combination with computing devices.

This application is a division of our copending application Serial No. 302,463, filed August 28, 1928.

The primary object of this invention is the provision of a recording device which may be operated efliciently at high speed and which responds to prepare accurately a record on a sheet in accordance with information transmitted thereto.

Another object of the present invention is to provide a computing and recording mechanism for eiiecting mathematical computations and recording the result of said computations on record sheets.

In accordance with the above objects, the present invention contemplates a perforating apparatus especially adapted for recording information in statistical and like cards by perforating apertures in differently allocated areas or zones of the cards. This apparatus includes a key board having a plurality of groups of keys, which groups correspond to the several areas or zones of the statistical and like cards. These keys serve to control the closure of circuits extending to a switching mechanism comprising a plurality of stationary contacts and a brush individual to each set of contacts, which brushes serve to complete electrical circuits through the contacts corresponding to the particular keys which have been operated in the various groups and the associated mechanism to selecting electromagnets embodied in the perforating apparatus.

In one embodiment of the invention, certain groups of the keys are designated as multiplicand and multiplier keys, respectively, on which a given problem may be set up, the product of which is desired to be recorded in an allocated area or zone of the statistical card.

The selecting electromagnets are mounted in arcuate, staggered relation to permit the location of a plurality of such electromagnets in a relatively small area and are energized in accordance with the depression of the keys of the key board which may condition circuits directly to the switching mechanism and/ or which may cause the operation of the multiplying mechanism to function in a manner to obtain the product of a designated multiplicand and multiplier. Individual to each of the selecting electromagnets is a selecting bar which is common to a plurality of perforating pins and which is adapted to be moved positively until it assumes a position in vertical alignment with a desired perforating pin which is determined by the time oi. operation of the selecting electromagnet. Specifically, the mechanism for effecting the movement of the selecting bars consists of a segmental gear which extends transversely of the selecting bars and which upon being rotated cooperates with a serrated portion of the selecting bars which are selected at different points in the rotation of the segmental gear through the operation of the selecting electromagnets and moved to positions in vertical alignment with the desired perforating pins.

Following the movement of the selecting bars in this manner, mechanical means is operated for causing the downward movement of a ram common to the perforating pins for positively moving the perforating pins selected in accordance with the movement of theselecting bars, thereby causing the numerals set up on the key board or the product resulting from the multiplication of the designated figures to be expressed in the card in the form of perforations or apertures.

In accordance with a specific embodiment of the invention, an unperforated card which is to receive the information in the form 01 perforations is advanced automatically to a position beneath the perforating pins, which advancement is in synchronism with the operation of the seg mental gear which efiectsthe movement of the selecting bars in accordance with their selection, as determined by the operation of the selecting electromagnets. Retraction of the perforated card is also effected automatically upon the restoration of the perforating ram'and it is consequently discharged into a hopper designed to receive it.

In the preferred embodiment of the invention it is proposed to efiect computations with a computing system using an electrical multiplying mechanism in which there are nine sets of nine each of electrical contact disks, each contact disk representing the'product of one digit by another digit and provided with an associated contact brush so that the position of a contact on onehalf of the circumference represents the unit' number of the particular product and a contact on the other half the tens part. The multiplicand and multiplier are set up on the groups of keys allotted to them to effect the closure of electrical circuits; whereby beginning with units, power is fed, for each digit in the multiplier, one at a time, through the contacts on the disks through distributing brushes to an accumulating device which completes electrical circuits to the contacts of the switching mechanism of the perforator. The di tributing b ushes transier the electrical connections from units to tens, tens to hundreds, hundreds to ten-hundreds, etc., at the proper point in each cycle. The entire product of a digit in the multiplier by the multiplicand is accumulated on the accumulating device for one revolution of the contact disks, When the final product is set up in the accumulating device the perforatoris operated to perforate a card in accordance with the result standing in the accumulator and the information set up on the key board.

The aboveand other features of the present invention will be fully set forth in the following description and appended claims, and will be more readily understood by reference to the accompanying drawings, wherein Fig. 1 is a plan view of the apparatus embodying the features of this invention;

Fig. 2 is a rear elevation of the apparatus shown in Fig. 1; I

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is also a sectional view taken on the line 4-4 of Fig. 2;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 2 and shows a part of the clutch operating mechanism and the drive through which power is communicated to the various parts of the apparatus;

Fig. 6 is a sectional view taken on the line 6--5 of Fig. 2 showing the arrangement of the gears through which power is communicated to sequence or contact switches;

Fig. 7 is a sectional view taken on the line 'I-| of Fig. 5;

Fig. 8 is a sectional view taken on the line 88 of Fig. 3 and shows in section the arrangement of the selecting bars and their associated perforating members;

Fig 9 is a plan view of a statistical record card in which information is expressed in the form of perforations;

Fig. 10 is a circuit diagram of the electrical connections employed in the operation of the perforating apparatus;

Figs. 11 and 12 are circuit diagrams which, when viewed collectively with Fig. 12 to the right of Fig. 11 disclose the electrical multiplying system which it is preferred to use in combination with the perforator shown in the other views;

generally by the respective numerals and will be described more in detail later.

1 Referring now to the key board which is shown in Fig. 1, a plurality of keys are arranged in various groups depending upon the character of the information desired in a statistical card of the character shown in Fig, 9, the keys making up the key board 5 are mounted in strips or rows in a manner similar to that described and disclosed in A. D. Hargan Patent No. 1,378,950, issued May 24, 1921. As disclosed in this Hargan patent. a member common to a plurality of keys is provided for maintaining the keys in an actuated condition once they are depressed. For the purpose of restoring the actuated keys to normal, an electromagnet 8 operatively connected to the member common to the keys has its operating winding connected with a suitable control circuit which, when closed, causes its energization and thereby the restoration of the depressed keys to normal. Inasmuch as the details of the key construction do not constitute a part of the present invention, a detailed description of the construction and operation of this part of the mechanism is believed to be unnecessary.

As previously mentioned, the key board 5 is divided into a plurality of groups of keys. Each Fig. 13 is a fragmentary front elevational view of the structure of the multiplying mechanism;

Fig. 14 is a vertical sectional view taken on the line llll of Fig. 13 in the direction of the arrows;

Fig. 15 is a fragmentary sectional view taken on the line l5-l5 of Fig. 13 in .the direction of the arrows;

Figs. 16 and 17 are sectional views taken on the lines l6--l6 and "-41, respectively, of Fig. 13 in the direction of the arrows showing one of the disk units on the multiplying commutator, and

Fig. 18 is an enlarged fragmentary schematic of three .of the nine sets of nine each of the contact disks representing the electrical multiplication system on the multiplying commutator.

In the practical application of the present invention, the apparatus utilized for the accomplishment of the objects of the invention consists of three principal parts, a key board 5, a computing or multiplying mechanism 6, and a perforating or punching mechanism I. Each of these just referred to parts of the apparatus embody the features of th s invent n have been designated of these groups of keys controls the operation of contacts indicated generally by the numeral ll (Fig. 4) which contacts serve to control the closure of electrical circuits to be explained later.

Positioned at opposite sides of the key board 5 are two elongated members l5 and 16 which function to control various starting operations of the apparatus. For example, the member l5 through suitable contacts associated therewith, when depressed, causes the closure of circuits extending to mechanism for setting into operation the computing or multiplying mechanism referred to generally by the numeral 6 (Fig. 10). Likewise, the member I 5 serves to control suitable contacts and consequently the closure of electrical circuits extending to apparatus for initiating the operation of the elements constituting the perforating mechanism indicated generally by the numeral I.

In order that the keys in the various groups of keys may be selectively connected to various other circuits, control mechanism indicated generally by the numeral I0 is provided. This mechanism consists of a plurality of jacks ll (Fig. 1) designed to receive plugs I2 and I 3 which are attached to opposite ends of a flexible cord II, By means of the flexible cord I4 and the plugs l2 and I3 various combinations of circuits may be established. The purpose and function of such flexible cords will be more fully described in the description pertaining to the operation of the apparatus.

The computing or multiplying apparatus which has been designated generally by the numeral 5 comprises mechanism controlled by the depression of keys in the respective groups of keys set apart for the multiplicand and multiplier for computing the desired problem.

The perforating mechanism comprises a plurality of electromagnets 25 arranged in an armate staggered relation to permit the location of a large number of such electromagnets in a relatively small area. Each of these magnets is provided with suitable armatures 26 shown more clearly in Figs. 2 and 3 as being operatively associated with pivoted, bell crank levers 21. According to the preferred embodiment of the invention, the electromagnets 25 are mounted on rectangular shaped members which are secured to side plates 2| and 22 on the arc of a circle and are arranged in a manner such as to permit the ready, easy and quick removal of an electromagnet without disturbing any of the other electromagnets. The axis of the are on which the rectangular shaped members supporting the electromagnets are mounted corresponds approximately with the pivotal point of the bell crank levers 21. These bell crank levers 21 are pivoted to a rod 23 and are moved from their normal position against the action of a spring 23 indfvidual to each bell crank lever. When the electromagnet is deenergized the spring 23 is effective for quickly returning the associated bell crank lever to normal. In order to. accommodate the springs individual to the levers 21 within a given area, two mounting plates 35 and 36 are displaced from each other and are secured to side plates 2| and 22,' thereby permitting the springs to be arranged in two rows, as shown in Fig. 3. Individual to each of the levers 21 is a selecting bar 3| which is engaged on its under side by a pin 33 secured to the free end of the bell crank lever 21. The selecting bars have on one surface a plurality of serrations or teeth 32, while on another surface a projection 33 is formed. The end of the bar 3| opposite to that carrying the serrations or teeth 32 is enlarged as indicated by the numeral 34.

The electromagnets 25 upon being energized elevate the bar 3| through the movement of the bell crank lever 21 to a point where the teeth 32 thereof are brought into engagement with a segmental gear 31. This segmental gear 31 is mounted transversely of the selecting bars 3| (Fig. 2) and is secured to a shaft 38 which is journaled in the plates 2| and 22. The shaft 38 (Figs. 2, 3 and 4) carries a gear 39 which is adapted to be oscillated by means of a rack 40 held firmly in engagement with the gear 39 by a flanged roller 41. The rack 40 is secured to an operating bar 4l which has its opposite end secured to one end of a lever 42 which is pivoted at 43. The lever 42 is of the shape shown in Fig. 4 and carries a roller 44 which cooperates with a cam groove 45 for causing the movement of the operating bar 4| and its associated rack 40 in accordance with the rotation of a cam 45. As is clear from the arrangement of the lever 42 and the cam 45 with which the roller 44 cooperates, the rack 40 will be reciprocated and will consequently impart to the segmental gear 31 through the gear 39 an oscillatory movement. Consequently, any of the selecting bars 3| which will be actuated in accordance with the energization of the electromagnets 25 during the oscillation of the segmental gear 31 in a clockwise direction will have the teeth 32 thereof moved into mesh with the teeth of the segmental gear 31 and will be moved to the left, as viewed in Fig. 3, a distance dependent upon the time in the cycle of movement of the segmental gear at which the teeth 32 of the bar 3| engage the teeth of the gear 31. Conversely, when the se mental gear 31 is operated in a counter-clockwise direction the selecting bars 3|, which were moved to the left upon the previous oscillation of the segmental gear 31, will be retracted to their normal position.

As previously described, a projection 33 is formed on a surface. of the bar 3|. This projection normallyengages a somewhat similarly shaped portion of a member 46 which extends transversely of the selecting bars 3| and which functions to maintain the se e t b i e gagement with the segmental gear 31 upon their operation by the electromagnets 25 and to disengage the selecting bars from the segmental gear upon their retraction to the position shown in Fig. 3. In further explanation of this operation it will be noted that the under side of the selecting bar 3| has a depressed portion 53 in which the projecting portion of the bar 46 normally rests. When a selecting bar 3| is elevated through the operation of the pivoted bell crank lever 21 and is moved to the left through the oscillation of thesegmental gear 31, it will be maintained in operative association with the segmental gear independently of the energization of the associated electromagnet 25, as the surface SI of the selecting bar 3| now rests on the bar 46. When the selecting bar 3| is retracted due to the oscillation of the segmental gear 31 in a counter-clockwise direction, and when it reaches a position where the groove 50 is in vertical alignment with the bar 46, the lip of the bar 46, will engage the projection 33 and cause the disengagement of the selecting bar 3| from the segmental gear 31.

The cam 45 through which the rack 43 is reciprocated is mounted on a shaft 52 which extends transversely of the machine and which is mounted to depending members 43 and 43 below the shaft 38. Also rigidly secured to the shaft 52 is a cam 53 which is provided with a cam groove 54 which is engaged by a roller 55. This roller 55 is carried by the free endof an arm 56, which is integral with and mounted substantially central to a shaft 51 (Fig. 2), which carries at its extreme ends arms 58 and 53 having connected thereto vertically extending links 60 and 6|. Connected to the opposite ends of the links 60 and 6| is a member or ram 63 which extends transversely of and above the enlarged portion 34 of each of the selecting bars 3| and which is reciprocated on vertical guides 66, 61, 63 and 69. As shown in Fig. 8, the member or ram 63 has a recessed portion 64 in which there is positioned a slotted member 65. This member is secured against movement, but the recess 64 is of a depth suflicient to permit a predetermined vertical movement of the member or ram 63.

The ends of the selecting bars 3| having the enlarged portion 34' slide in the slots or grooves formed in the member 65 and are thereby guided when moved to the left or right (Fig. 3) depending upon the direction of rotation of the segmental gear 31. Positioned below the member 65 and secured to and movable with the ram 63 is a plate 10 having apertures arranged to receive perforating pins 1|. In the particular embodiment of the invention disclosed in the drawings, the perforating pins 1| are arranged in forty-five rows with ten pins to each row, making a total of four hundred and fifty perforating pins 1|'. Each of these perforating pins is provided with a shoulder 12 which normally rests on the upper surface of the plate 10. When a selecting bar 3| is moved to the left (Fig. 3) a distance depending upon the time at which it was caused to engage the teeth of the segmental gear 31, a. perforating pin in the particular row of perforating pins to which a selecting bar 3| is common will be selected for operation. That is, for each movement of the selecting bar 3| only one of the perforating pins 1| of the row of pins to which that particular selecting bar 3| is common will beselected for subsequent actuation, since the enlarged portion 34 thereof is of such dimension as to cover only one per forating pin 1|. The actuation of the selected perforating pin 1| is effected through the down-- ward movement of the ram 83 by the cam surface 54;"which causes the perforating pins 'II to be positively depressed into operative association with aligned apertures 13 formed in a die plate 14'which is rigidly mounted to the base plate 24. and the apertured member are two similarly apertured plates 18 and 11 which are secured to opposite faces of blocks 18 and 19 which are supported by the base plate 24. Inasmuch as the apertures in the plates 10, 18 and 11 are in ver tical alignment with the apertures in the die plate 14, the perforating pins II will be accurately guided. The plate 11 is spaced from the die plate 14 a distance suflicient to allow the passage of a record sheet or card therebetween. When the cam surface 54 reaches a predetermined position in its rotation, arm 58 will be moved downwardly for causing the upward movement of the ram 63. Plate 10 being moved with the ram 83 and being engaged by the shoulders 12 on the perforating pins 1I, elevates the actuated perforating pins to the position shown in Fig. 8.

As is clearly shown in Figs. 1 and 3, the machine is provided with an inclined table 82 which is mounted above and substantially central to the key board 5. The table 82 is arranged to receive a record sheet or card which is desired to be perforated in accordance with certain predetermined operations of the keys in the various groups of keys making up the key board 5.

Following the placement of the record sheet or card on the table 82 and synchronously with the operation of the segmental gear 31, mechanism is operated for automatically advancing the sheet or card to a position below the perforating pins 1I. This mechanism comprises a pair of oppositely disposed feed fingers 83 and 84 which, upon being moved, engage the sheet or card and positively advance it along the table 82 to a position where it is engaged by positively driven rollers 85 and 88. While the roller 85 is positively driven it is also pivotally'mounted at 81 (Fig. 4) and held in operative association with the roller 88 by means of a coil spring 88. The feed fingers 83 and 84 are operated momentarily by means of a leverage arrangement which is reciprocated in synchronism with the oscillation of the segmental gear 31, by a cam 92 which is secured to the cam 53,but on the opposite side to the cam groove 54.- Specifically the mechanism for moving the feed fingers 83 and 84 comprises a. pivoted lever having arms 93 and '94. To the arm 93 is secured a roller 95 which engages the cam surface of the cam 92 and which upon such engagement causes the movement of a collar 98 which is mounted loosely on a rod 91. Movement of the rod 91 is effected through a collar 98 rigidly secured thereto and a. spring 99 which is interposed between the collars 98 and 98. Operatively associated with the arm 94 is an adjustable screw I08 which limits the movement of arm 93 and insures the proper engagement of the roller 95 with the cam 92. Secured to the end of the rod 91 opposite to the end on which the sleeve 98 is loosely mounted is a bar IOI which extends transversely of the table 82 and to which there is rigidly secured a U-shaped member provided with arms I82 and I03. Each of the arms I02 and I03 carries a link I04 which is normally under the Interposed between the die plate I4- a transversely extending bar I88. The feed fingers 83 and 84 are secured to the bar I08, and since the top of the table 82 is slotted at I01 (Fig. 1), the fingers 83 and 84. are capable ofbeing moved upon the movement of the rod 91 and its associated U-shaped member including the arms I02 and I03.

When the feed fingers 83 and 84 are moved in the manner just described, and provided 8. record sheet or card had been placed on the table 82, it will be advanced to a position where it is engaged by the rollers 85 and 88, after which the feed fingers will be retracted to a position to receive another card. These rollers (Fig, 5) are driven from the shaft 38 which carries the segmental gear 31 through a train of gears consisting of gears H2, H3, H4, H5, H8, III, H8, H9, I20, HI and I22. It will thus be seen that the rollers 85 and 88 which are secured to gears HI and I22, respectively, will be driven through the train of gears just referred to in synchronism with the oscillation of the segmental gear 31 and will, during the movement of this gear in.

one direction, be rotated in a direction for moving the record sheet or card into alignment with the perforating pins 1|, and in an opposite direction for causing the retraction of the record sheet or card upon the rotation of the segmental gear 31 in a direction opposite to that which caused the forward movement of the selecting bars 3|. The advancement and retraction of the record sheet or card is also facilitated by means of the rollers I 23--I 23 and I24I24 which are positively driven through gears H1 and I I9, respectively, and which are operatively associated with spring pressed rollers I25-I25 and I28- I28, respectively. As shown in Figs. 4 and 8, the rollers I25 and I28 are interposed between the plates 15 and 11 having a portion thereof pro- ,iecting through the plate 11 and are pivotally mounted at I21I 21 and I28I28, respectively, resilient means I29I29 being provided for holding the respective rollers firmly in contact with the rollers I23-I23 and I24I24. The forward movement of the card is arrested by a stop member I3I located between the die plate 14 and the plate 11. Like the rollers 85 and 88, the rollers l23--I23 and I24'I24 will be rotated first in one direction'to advance the card and thenin a reverse direction to retract the card in accordance with the oscillation of the segmental gear 31.

mounting of a spring I34 which is formed with ten ion of a spring I05 and which is secur d to projecting portions I35 which extend into the cut-out portions I33 of the rollers and 88. A card in being advanced by the feed fingers 83 and 84 causes the depression of the spring I34 upon its engagement by the rollers 85 and 88. It will thus be apparent that the projections I 35 of the spring I 34 are directly in the path of the perforated card as it is being ejected and will cause the card to be diverted along a different path than it traversed upon its advancement to be perforated. "When the card is deflectedby the projections I35 of the spring I34, the edge thereof strikes a surface I31 of spring pressed members I39I39 which cooperates with a surface of member I38 to cause the card to assume a horizontal position on the bottom of a hopper I38, as shown in Fig. 3.

Power for driving the shaft 52 is communicated from an electric motor (not shown) through a belt I 40, and a continuously rotating pulley wheel I which is secured to a shaft I42 to which there isalso secured a worm wheel I48 (Fig. 2). The worm wheel I48 engages a worm gear I44 which is rigidly secured to a stud shaft I45. Also secured to the shaft I45 is a serrated member I45 of a clutch mechanism designated gen- 5 erally by the numeral I41. Positioned opposite to and on the driven shaft 52, the shaft I45 being referred to as the driving shaft, is a pivoted member I48. The pivoted member I48 is normally urged to the right. as shown in Fig. 7, by a coil spring I49 mounted in a housing I58 in the free end of the pivoted member I48. A projecting portion I5I of a collar secured to the driven shaft 52 forms a base away from which the spring I49 urges the pivoted member I48. The pivoted member I48 has aresilient wedge-shaped member I52 positioned therein and urged in an upward direction (see Fig. 5) by a spring I55. The pivoted member I48 also has a finger I54 at the extreme end thereof opposite the pivot point. The shaft 52 is supported by supporting member 49 upon which is also mounted an electromagnet I58 having an armature I58 which is urged away from the electromagnet by a spring I59. Formed on the end of the armature I58 is a detent I58 which engages a member I5I pivoted on the support 49.

When the electromagnet I55 is energized, the detent I50 will be moved downwardly (Fig. '7) or to the left, as viewed in Fig. 5, thus releasing the pivoted member I5I which, together with the pivoted member I48, will be moved to the right (Fig. '7), by the action of spring I49. Consequently, the wedge-shaped member I52 will be forced to engage the serrated portion of the continuously rotating member I45. Just prior to the completion of the cycle of rotation of the pivoted arm I48, the projecting finger I54 engages a cam surface I52 mounted on the member I5I for causing the spring actuated detent I58 to engage the pivoted member I5I and restrain it against movement to the right, as viewed in Figs. 2 and 7. In the further movement of the finger I54, cam surface I1'] is engaged, thereby resulting in the movement of the pivoted member I48 to the left (Fig. '1) and the disengagement of the wedgeshaped member I52 from the serrated portion of the member I45. The elements just described will remain in this position until the subsequent energization of the electromagnet I55.

In addition to the cams 45 and 53, a gear I54 is also mounted on the driven shaft 52. This gear meshes with a gear I55 which in turn meshes with a gear I secured to a stud shaft I51 (Figs. 2 and 6). The stud shaft I51 is mounted parallel to the shaft 52 and has mounted thereon at spaced points contact operating members I58 and I59. These contact operating members preferably consist of insulating and contacting portions which in the course of their rotation are operatively associated with contact brushes I18I13 and I14I14, respectively, which are mounted on opposite sides of the respective contact operating member I 58 and I59. As will be described more in detail hereinafter, the contact operating members I58 and I59 control the completion of circuits extending from the contact brushes I13 and land specifically function to insurethat the electromagnets 25 will be energized only during the forward stroke of the sele'cting bars 3| and thatthe actuating keys of the key board 5 and the operated elements of the computing or multiplying mechanism 5 will be restored to normal.

The completion of circuits established through 75 the actuation of the keys in the key board 5 and the elements of the computing or multiplying.

mechanism 5 is effected to the electromagnets 25 of the perforating mechanism 1 through a switching mechanism indicated generally by the numeral I15. The switching mechanism I15 consists of a plurality of arcuate banks of conmounted on a shaft I84 which also carries a gear I85 (Fig. 4). Meshing with the gear I85 are the teeth of a rack bar I85 which are held in operative association therewith by a flanged roller I81. The upper end of the bar I85 has teeth formed at right angles to the surface at which the teeth which engage the gear I85 are formed, which teeth engage a gear I88 which is secured to the shaft 85. Intermeshing of the teeth of the gear I88 and the teeth formed on the upper part of the bar I85 is also effected by means of a flanged roller I59. From this description of the switching mechanism I15 it will be seen that circuits which are connected with contacts I98 will be progressively completed upon the rotation of the brush I11 individual to thebank of contacts including the particular contacts connected with the actuated keys of the key board 5 or the elements of the computing or multiplying mechanism 5 which are at that particular time operated.

In further explanation of the switching mechanism referred to generally by the numeral I15, the small rectangles in the upper right hand comer of Fig. l designated by the numerals I95, I95, I91, I98, I99 and 208 are intended to indicate the location of switching mechanism similar to that designated by the numeral I15. However, for the sake of clarifying the drawings the details of the switch mechanism in this particular figure have been omitted. Contained in each of the rectangles I to 280, inclusive, are a plurality of arcuate banks of contacts with a rotatable brush individual to each bank of contacts. In the specific embodiment of the invention disclosed there are included in the several banks of contacts a total of five hundred and thirty contacts. Of this number four hundred and fifty are connected to the key board 5 independent of the computing or multiplying mechanism 5, while the remaining eighty contacts are allotted to the computing or multiplying mechanism 5. As previously mentioned, the perforating mechanism includes a total of fortyfive electromagnets. These electromagnets are adapted to be connected to the brushes of the respective switching mechanisms and are ener gized momentarily upon the passage of the 'brush individual thereto over a contact in the arcuate bank of contacts which is at that particular instant connected with battery either directly through the contacts of a depressed key of the key board 5 or the operating elements of the multiplying mechanism 5 and the'contact controlling switch I58.

It is believed that a clear understanding of the parts of the apparatus described previously will be had from a detailed description of the operation of the various elements embodied in the apparatus. As previously noted, the key board I is preferably divided into a plurality of groups of keys, which groups may be allotted to control the perforation of expressions for certain predetermined information. As shown in Fig. 1, the keys are arranged in rows of ten keys each, the upper key in each row being referredto as the repeat key. That is, when it is desired to perforate a second card or other cards in accordance with a previous setting of the key board, the key designated as the repeat keyis depressed, which, as will be more clearly explained hereinafter, functions to prevent the release of the previously depressed keys.

Before entering into a detailed description of the operation of the apparatus for a given problem, it will first be explained that the various .rows of keys are adapted to control the energization of electromagnets 25. This feature is accomplished by means of groups of jacks designated generally by the numeral II and designated specifically by the group numerals 20!, 202 and 203 which, for the sake of clearness, will be referred to as the key board lacks, the per-' forating jacks,- and the product jacks, respectively. Thegroup of jacks 20I are connected.

directly to the contact brushes cooperating with the contacts of the keys of the key board 5, while the group of jacks 202 are connected directly to the windings of the electromagnets 25, and groups 203 are connected directly to the contact brushes cooperating with the output elements of the multiplying mechanism 6.

Assume now that the first five rows of keys and the next three rows of keys of the key board are allotted to the multiplicand and multiplier, respectively, and that it is desired to perforate in a record sheet or card information expressing the multiplicand and multiplier in the form of perforations in the first eight allotted columns of the record sheet or card. In order that the depressions of the multiplicand and multiplier keys will be indicated in these particular areas of the card, flexible cords I4 are employed for interconnecting the first eight jacks in the horizo'ntal rowof jacks 20l with the correspondingly numbered jacks in the group of jacks 202. With such circuits established, the electromagnets 25 of the perforating mechanism will be interconnected with the rotating brushes ll! of the first eight banks of arcuate banks of contacts I95, which contacts are connected directly to the contacts of the keys, as indicated in Fig. 10. Let it further be assumed that it is desired to perforate the card in accordance with certain departmental information such as, for example, the department number, and that the next three rows of keys following the row of keys set apart for the multiplier are-allotted to the departmental information. In like manner the keys in the last mentioned rows of keys will be interconnected with the rotating brushes I" of the last two banks of contacts in the arcuate banks of contacts I95, and the first bank of contacts in the arcuate banks of contacts I96 with the electromagnets 25 by means of the flexible cords I l.

The product resulting from the multiplication of the digits of the multiplicand and multiplier may be perforated in any of the remaining areas of the record sheet or card. Although the keys in the first eleven rows of keys have been described as controlling the perforations in the first eleven columns on the card, these keys may be connected by means of the flexible cords It so as to effect the perforation of the information inany column. For the purpose of illustration, columns 3| to 20, inclusive, of the card have been set apart to receive the product. The rows of keys for the various digits of the multiplicand and multiplier have additional contacts which are connected directly, as shown in Fig. 10, to the multiplying mechanism 6, which, in turn, has its operating elements connected to contacts of the first eight banks of contacts in the arcuate banks of contacts 200. These contacts may be interconnected with the electromagnets 25 by the rotating brush I11 individual to the particular bank of arcuate banks of contacts connected to the multiplying mechanism 6 by flexible cords I connected to the eight jacks of the group of jacks 203 and the jacks numbered 3| to 38 of the group of jacks 202.

Let it further be assumed that it is desired to compute the cost of the work done by a certain department, for example, a department having the number assigned thereto. and whose average rate is six dollars and seventy-eight cents with a cross (x) on the key board 5 will be depressed. The depressed keys indicate the multiplicand, the multiplier, and the number of the department, respectively.

In order to bring out more clearly the flexibility of a key board of this type, it will be assumed that it is not desired to compute the cost of the work in thousandths and ten thousandths parts of a dollar. To accomplish this object it is necessary to simply connect thejacks 1 to 6 of group 203 to jacks 33 to 38 of group 202, thus dropping the last two decimal points of the product, and shifting the product so that the last denominational column on the card will have perforated therein the one-hundredth part of a dollar in the product.

Referring now to Fig. 10 which shows schematically the circuit connections for one row of keys, this circuitis typical of all of the other rows of keys, excepting those which are not connected with the multiplier 6. As shown in this figure, the contacts of'the keys are connected to the contacts of one of the arcuate bank of contacts I16 and the multiplying mechanism 6, which in turn is connected with the contacts of another bank? of contacts of the arcuate bank of contacts I16.

In the problem selected for illustration, the key 201 numbered 1, counting from left to right as viewed in Fig. 10,15 depressed. The depression of key 201 closes contacts 200 and 209, the contact 208 being connected through conductor M0 to contact 2| l, of one of the arcuate banks of contacts I10. Contact 209 of the key 201 is connected through conductor M2 to the multiplying mechanism 6. The depression of the key 201 or any of the other keys also causes the bar 2l3 which is common to all of the keys with the exception of key 2 which is designated as the repeat key, to be moved to the left, as viewed in Fig. 10, for openingcontact 2l5. This operation results due'to the location on the'bar 2l3 of pins 2l6 which are mounted on the left of therespective keys and which are engaged upon the keys to which the electromagnet 8 is common, as described in detail in the aforementioned patent. The operating circuit of the electromagnet 8 extends from battery through the right hand brush I18 (Fig. 2), the conducting plate 222 of contact member I88, and the right hand brush I18 (Fig. 6), momentarily at a predetermined point in the cycle of rotation of the contact member I88, conductor 228, contact 224, winding of the electromagnet 8, contact 2" (closed on depression of any of keys 1 to 9), and conductor 228 to ground. Likewise, circuits similar to those just described will be established upon the depression of the other keys in the respective rows of keys of the multiplicand and multiplier. In the event that there is no key in any of the various rows of keys depressed, contact 2I8 is maintained closed, which completes the circuit to contact 2I8 of one of the arcuatevided in the rows of keys on the key board.

However, if it is desired to perforate an aperture in the card in the position allocated to zero, no key need be depressed and the perforation of zero will be automatically accomplished through the contacts of the key structure shown diagrammatically in Fig. 10.

Circuits having been established through the depression of the various keys to the multiplying mechanism 8, the elongated member I8 is depressed, which causes the closure of a starting circuit (not shown) extending to the multiplying mechanism 8. Upon the completion of this circult, the elements of the multiplying mechanism 8 are set in operation and function to compute the product of the particular problem. The multiplying mechanism having performed its function establishes through its elements, circuits extending to contacts in the various banks of arcuate banks of contacts 200. Also assuming that the arcuate bank of contacts shown schematical- .ly in Fig. 10, as associated with the multiplying mechanism 8, is the bank of contacts associated with jack numbered 8 of group of jacks 208, the product which will be transmitted by the multiplying mechanism to the jacks 208 will, in this specific instance, be 910.2150. Since this product will be transmitted to jacks 2 to 8, respectively, of group 208, and further since the jacks '7 and 8 which would have transmitted thereto impulses to control digits 5 and 0, respectively, have not been connected to any of the group of jacks 202, these digits will not be perforated in the card due to this break in the circuit. However, since jack numbered 6 of group 208 has been connected to jack 38 of group 202 by means of the connecting cord I4, the contact 228 will have ground supplied thereto by the multiplying machine. Likepivotedmember I48 to move to' the right, as

' viewed in Fig. 1. The movement of the pivoted the first contacts in each of the banks of arcuate member I48 causes the wedge-shaped member I82 to engage a serration in the continuously rotated member I48. Consequently, power is communicated to the shaft 82 from the continuously driven shaft I48, through the serrated member I 48 and the pivoted member I48. Th shaft 82 in rotating carries with it cams 48 and 88 and gear I84.

The cam 48, as described in detail, actuates the pivoted lever 42 which causes'the reciprocation of rack 40 through the operatingbar 4I. Oscillation of the gear 88 is thereby efl'ected for causing the corresponding oscillation of the segmental gear 81. synchronously with the oscillation of gear 88, gear I88 which is secured to the same shaft is oscillated for causing the reciprocation of rack bar I80 which, through gear I18, rotates shaft I18 on which the brushes I11 individual to the respective banks of arcuate banks of contacts I18 are mounted. As the brushes I11 pass over banks of contacts, a circuit will be established to theelectromagnet 28 of the perforating mechanism 1, provided ground was previously connected vto those particular contacts of the arcuate banks of contacts. However, the completion of the circuits to the electromagnets'28 is controlled by contact switch I88 which is rotated through gear I84 and which connects all of. the electromagnets .gages contacts 2 and 228, circuits will be momentarily established to the electromagnets 28 which are connectetthrough flexible conductors I4 to the brushes individual to thes banks of contacts. The electromagnets 28 upon being energized cause the operation of bell crank levers j 21 for elevating the selecting bars 8| individual wise, contact 2I I of another bank of arcuate bank of contacts 118 will be connected to ground but thereto into contact with the segmental gear 81. The segmental gear 81 now being rotated causes the movement of the selecting bars 8| to the left until they are in vertical alignment with the second perforating pins H of the respective rows of perforating pins (Fig. 3). The movement of the selecting bars 8I to the second position is due to the fact that the segmental gear 81 has substantially completed its oscillation in a clockwise direction and due to the fact that the brushes I 11 have previously passed over eight contacts I80.

In the specific problem stated hereinbefore for figuring the cost of certain work, the brushes I11 in passing over the contacts I80 will first energize the electromagnets 28 controlling the selector bar 8I associated with the 9th and 34th row of perforating pins H and will thereafter, at regular intervals, energize successively the electromagnets 28 which control the selector bars 8| associated with the 8th, 7th, 6th, 5th, 3d, 2nd rows, the 4th and 7th rows simultaneously, the 1st,

- 11th, 35th, and 38th rows simultaneously, and the detent I80 which allows the member I8I and the 10th and 36th rows simultaneously. Upon the actuation of these electromagnets 28, as pointed V out hereinbefore, the selecting bars 8I will be drawn into engagement with and driven forward by the segmental gear 81, and since the electromagnets 25 controlling the 9th and 34th rows of 32 into operative relation with roller 98 which,

through rod 81 and its associated elements moves a card 221 engaged by the feed fingers 83 and 84 into association with the rollers 85 and 88 which rollers engage the card and advance it to a position where it is engaged by the rollers I23 and I24. These latter rollers advance the card 221 to a position against a stop I 3|. Shortly after the:

movement of the fingers 83 and 84, cam groove 34 of the cam 53 is rotated to a position where the roller 85 is effective to elevate arm 58. The elevation of the arm 58 causes the downward movement of the ram 83, and since the selecting bars 3I are now in their selected position, the perforating pins H on which the enlarged portion 34 of the selecting bars'3l rests, will be depressed to cause the card 221 positioned between the die plate 14 and the plate 11 to be perforated as shown in Fig. 9.. Upon the continued rotation of the cam 83 and due to the shape of the cam groove 54, the arm 58 will be moved downwardly, causing the upward movement of the ram 83 which carries with it the apertured plate 18 and the depressed perforating pins 1I. Further retraction of the perforating pins 1| is prevented due to the slotted member 65.

At this point in the cycle of operation the cam 48 is in a position where the rack 48 is being moved downwardly, resulting in the oscillation of the gear 38 and the segmental gear 31 in a counter-clockwise direction. Consequently, those selecting bars 3| which were moved to the left, as viewed in Fig. 3, will be moved to the right and will be caused to assume the position shown in this figure by-the lip of the bar 48. The perforating card 221 is, during the oscillation of the segmental gear 31 in a counter-clockwise direction, moved from beneath the perforating pins 1i due to the rotation of the rollers I23 and I24 in a counter-clockwise direction. Due. to the location of the projections I35 of the spring I34, the perforated card 221 will be deflected into the hopper I38. Also synchronously with the oscillation of the gear 39 the gear I18 is oscillated in a direction to restore the brushes I11 of the several banks of arcuate banks of contacts I18 to normal.

Just subsequent to the time the selecting bars 3| reach the extreme point in their movement to the left (Fig. 3), contact switch I61 is effective for causing the release of the operating elements of the multiplying mechanism 8 in a manner more fully described later in the specification. Also following the opening of the circuits to the electromagnets 25 and about the same time that the contact switch I61 is eiiective, contact switch I88 completed a circuit extending tothe electromagnets 8 of the various rows of keys in the key board 5. Provided the repeat key 2 has not been depressed, the electromagnets 8 will be energized over a circuit previously traced, causing the restoration of the depressed keys.

Inasmuch as the previously depressed keys have been. returned to normal, the machine is in readiness to receive a new problem. r-eeu fingers 83 and 84 being at that time in'their retracted position or the position shown in Fig. 1, an unperforated card may be associated therewith for subsequent advancement to a position where it will be perforated. The operator may now depress the desired keys in accordance with the new problem to be computed, the product of which will be perforated in the card now positioned on table 82.

Just previous to the completion of the cycle of rotation of the shaft 52, the finger I54 engages the wedge-shaped surfaces I82 and I18 for restoring the detent I68 to normal and disengaging the wedge-shaped member I52 from the serrations of the member I46, thereby stopping shaft 52 and its associated mechanism.

Although this invention contemplates the use of a perforator of the type described in detail hereinbefore in combination with any one of a number of well known types of calculating machines, a preferred computing mechanism, which has been designated generally by the numeral 8, will now be described.

The bank of five keys which have been allotted to the multiplicand and the bank of three keys which have been allotted to the multiplier are designated generally by the numerals 388and 38I, respectively. These banks are represented schematically in Fig. 11 by coordinate groups of lines, the vertical lines or columns from right to left denoting units (U), tens (T), hundreds v (H), ten-hundreds (TH), and ten-thousands (TI) and the nine rows of cross lines designating the digits 1 to 9 consecutively. Each intersection of the lines represents an electrical contact, normally open, which can be closed by the actuation of its associated key 281 on the keyboard.

Any particular problem of multiplication can be set up on the key banks 388 and 38I by closing the contacts at the points corresponding to the digits in the multiplicand and multiplier. These contact closures complete electrical circuits through a multiplying commutator 388 and send electrical impulses to a distributor switch denoted generally 386 which directs the impulses to an accumulator 381 for properly accumulating the results.

The multiplying commutator 385 comprises an electrical multiplication table in which there are nine sets, designated as 383, of nine each of electrical contact disks insulated from each other and divided into twenty-seven units of three each, designated by the numeral 384, so adapted that each contact represents one of a series of numbers representing the product of each digit times itself and each other digit running from 81 to 81. Each of the nine sets 3830f nine contact disks represents the numbers 1 to 9 consecutively and are connected to individual conductors leading to the corresponding digit in the multiplicand key bank 388. The contact disks are insulated from and secured to a rotatingshaft 388 journaled in bearings 388388 fastened to a frame 3I8 (Fig. 13). by means of a gear 3I5 fastened thereto and meshing with a spur gear 3I6 of a speed reducer 3I1 which is driven by a belt 3" froma motor 3I8 rigidly secured to the frame 3I8. Each unit 384 of three contact disks is also provided with an associated feed disk 348 (Fig. 16) for making connections with the digit cross lines of the multiplicand key bank. The contact disks have individual brushes and are so constructed that The shaft 388 is rotated' the position of the contact on one-half of the circumference represents the unit number of the particular product of two digits and a contact on the other half the tens part.

Figs. 16 and 17 show one of the units 304 of three disks 325, 328 and 321 representing the products of multiplying 2 by 1, 9, and 2, respectively. These disk units 304 are similar in construction to sequence switches commonly used in telephone exchange systems. The three copper disks 325, 326 and 321 are mounted on an insulator 328 and are electrically interconnected due to the fact that the disks 326 and 321 are integral and are connected with the disk 325 by means of copper rivets 329 passing through the insulator and serving to hold the elements together as the unit 304. The insulator 328 is keyed to the commutator shaft 308 and insulates the associated copper disks therefrom. Disk 325 has one radial contact 332 representing the prodnot 02 of 2x1 to be engaged by a brush 333 at a predetermined point in the rotation of the unit 304; the disk 326 has two radial contacts 334 and 335 representing the tens digit 1, and the units digit 8 of the product 18 of 2x9 to be engaged by a brush 336; the disk 321 has a contact 331 representing the product 04 of 2X2. to be engaged by a brush 338. A feed brush 338 contacts continuously (a triangular headed arrow denotes a brush which is always in contact) with the feed disk 340 which is shown in Fig. 16 as being integral with disk 325. The brushes, as shown in Figs. 11 and 18, are connected through conductors to the multiplicand and multiclier key banks. The above described unit was selected for purposes of illustration and it will be understood that the other units areof similar construction and are analogous to sequence switches used in telephone systems.

Fig. 18, the enlarged fragmentary schematic of the multiplying commutator, shows the arrangement of the multiplication table for three of the sets 303 representing the digits 1, 2 and 3. The multiplication table as illustrated follows the series of 1x1, 1 9, 1x2, 1x3, 1 4, 1 5, 1x6, 1x7, and 1x8; 2X1, 2x9, 2x2, 2x3, 2 4, 2x5, 2x6, 2x7, and 2x8; 3x1, 3x9, 3x2, etc., wherein each of the contacts represents a particular product. The multiplication table follows the usual order except that the digit 9 is laced between the digits 1 and 2 to simplify this point, as previously mentioned, that the units part of a product of two digits is registered during the first half revolution of the multiplying commutatonthat is, positions one to fourteen, inclusive, and during the second half of the cycle, positions fifteen to twenty-eight, inclusive, the tens parts is registered where the product consists of two digits (more than nine).

The distributor switch 306 (Fig. 11) is provided for transferring the electrical connections from units to tens, tens to hundreds, hundreds to ten-hundreds, etc., as the multiplication progresses to complete an electrical circuit to the the interconnecting of the circuits. It will be clear that the multiplication tables for the numbers 4 to 9, inclusive, are followed in a similar manner throughout the length of the multiplying commutator.

Secured to the multiplying commutator shaft, but electrically insulated therefrom, is a control commutator 345 (Fig. '12) consisting of circular switches K, L. and M for closing and opening arious circuits at predetermined intervals throughout the multiplying cycle, the full purpose of which will become apparent as the description progresses.

A dial 346 (Fig. 13) attached to the commutator shaft 308 and rotatable therewith is divided or marked to indicate twenty-eight equal parts so that each division marking indicates a particular rotative position of the shaft 308 and its associated disk units 304 rigidly mounted thereon relative to a fixed starting point. The positions one to twenty-eight are adopted to more clearly describe the sequence of events as the multiplying commutator 305passes through one complete revolution, and it is to be noted at proper electromagnets in the accumulator 301. The distributor switch is similar in design to selector switches used in telephone systems and comprises in general a shaft 341, an electromagnet 348 (Fig. 12) for rotating. it one step at a time, six brushes 348 to 354, inclusive (Fi 11), insulatively mounted on the shaft, and arcuate banks 344 of twenty-two stationary contacts adapted for cooperation with said brushes. Five of the brushes 348 to 353, inclusive, designate and may be connected by conductors to the units (U), tens (T), hundreds (H), ten-hundreds (TH), and ten-thousands (TT), columns in the multiplicand key bank 300. The sixth brush 354 applies ground progressively to one of the columns indicating units (U), tens (T), and hundreds (H), in the multiplier key bank 30| as the multiplication progresses to close the circuit therefrom through the multiplying commutator 305, multiplicand key bank 300, distributor switch 306, and the accumulator 301 to battery and ground.' The accumulator 301 can be remotely situated from the multiplicand and multiplier key banks to accumulate products of the multiplication, and comprises eight rotatable brushes 360 to 361, inclusive, representing units (U) to ten-millions (TM) columns in the final product, respectively, which brushes are adapted to make wiping engagement with an arcuate bank of contact 368 having stationary terminals number 1--2--3-4-5-6-7-8-90. The stopping of a brush on a particular terminal indicates that the number marked on the terminal at which the brush has stopped, has been accumulated in the accumulator and therefore that I The rotation of the accumulator brushes 360 to 361, inclusive, is accomplished by an electromagnetically operated means which will now be described. Referring to Figs. 12, 13, 14, and 15 of the drawings, a shaft 311 suitably journaled on the frame 3l0 has a gear 312 secured thereto meshing with an idler gear 313 which in turn meshes with the gear 3l5 driving the shaft 308 of the multiplying commutator 305. The rotating shaft 311 has rigidly mounted thereon a plurality of spaced gears 314 adapted to drive gears 315 (Figs. 13 and 14) fastened to shafts 316 carrying loosely mounted sleeves 311 to which thebrushes 360 to 361 are rigidly secured. Slidably keyed to and rotatable with the shaft 316 is a clutch member 318 having a serrated face 319 for'engaging a companion serrated face 380 of the sleeve 311 to cause rotation thereof. The slidable and rotating clutch member 318 is provided with a groove 384 into which extends the bifurcated end of an armature 385 of an electromagnet 386 of any suitable type. A compression spring 381 is associated with the armature 385 to separate the driving clutch member 318 from engagement with the brush carrying sleeve 311 when the eiectromagnet 388 is deenergized. From the foregoing it will be obvious that the energizing of the electromagnet 388 will move the armature 385 thereof to compress the spring 381 and lock the serrated faces of the clutch member 318 and the sleeve 311 together tojcause the rotation of its associated brush.

An index or register wheel 388 integral with each sleeve 311has a series of twenty depressions on its periphery, which depressions are adapted to be engaged by a roller 388 mounted on a compression leaf spring 388 to center the brush with respect to the position of the stationary terminals in the arcuate bank 368. Each depression has a number engraved therein starting with 1 and running consecutively as 2, 3, 4, 5, 6, '1, 8, 9 and so that there are provided two complete sets of indicating numbers on each register wheel. These numbers are so positioned on the periphery of the wheel that the depression immediately above the roller 388 indicates the number designated by its associated brush. For example, in Fig. 14 the brush 381 has stopped on the terminal 9, and the operator by looking at the depression 38l immediately above the roller,

reads the number 9 engraved therein. The use of the two complete sets of indicating numbers on each register wheel 388 gives a rapid indica tion in that a digit is registered for each half revolution of the register wheel.

In order to facilitate an understanding of the working relationship of the details of the com. puting system and to afford a more effective means of describing many important functions thereof such as the carry function of the accumulator and its method of simultaneously carrying tens to higher denominational orders, an explanation will be given of the steps performed in a specific example such as multiplying 72293 by 159. It will be noted at thls'time that the problem selected for illustrating the operation of the multiplying mechanism is not the same as that selected for illustrating the operation of the perforating mechanism. However, the problem selected for illustration in connection with the perforating mechanism was of the type which brought out most clearly the operation of the 4 machine from a practical standpoint and the problem selected for illustrating the operation of the multiplier is taken for the reason that it discloses clearly such features as the carry function of the accumulator and the multiplication of a multiplicand by a multiplier having the digit 9 in one of its denominations.

In order to accomplish this multiplication the driving motor 3l8 (Fig. 13) is connected to a suitable source of power (not shown) to cause continuous rotation of the multiplying commutator 385 and of the shaft 316 of the accumulator switch 381 as has been previously described. Keys 281 on the keyboard 5 (Fig. 1 shown diagrammatically in Fig. 11) in the multiplicand and multiplier key banks 388 and 3M corresponding to the numbers 72293 and 159, respectively, are then depressed as indicated by the circles (Fig. 11) to close electrical circuits at those points. The operator then momentarily presses the start key [5 which closes a circuit from grounded battery 388, conductor 381, and the winding of a starting relay 388 to ground. Relay 388, upon being energized, establishes a locking circuit. for itself from ground through its winding and right hand contact and armature, conductor 388 and the winding of the electromagnet 348, of the distributor switch to grounded battery. The current flowing through the distributor magnet 348 at this time is not sufficient to operate it, but it is suiiicient to maintain relay 388 energized. The closure of the left hand contact of relay 388 connects brush 4 of the circular switch M of the control commutator 345 to ground, through conductor 48l, conductor 458 and the b ck contact of clearout switch 482. When the con rol commutator 345, which runs continuously as a part of the multiplying commutator 385, reaches position I, as indicated by the dial 348 -(Fig. 13), a circuit is established through brushes M4 and M2, conductor 483, left hand winding of a pickup relay 484, conductor 3 and the backv contact and armature of a release relay 485 to grounded battery. Pickup relay 484 is thereby energized and establishes a locking circuit for itself through its right hand inner contact.

The operation of the pickup relay 484 also establishes a circuit from ground through brushes L4 and L2 of the control commutator 345, conductor 488, left hand inner contact of relay 484, conductor 4|8, conductor 388 to the winding of distributor switch magnet 348. The circuit Just traced is closed for 25 of rotation from position I of the control commutator and performs two functions: it operates the distributor switch magnet 348, advancing the distributor brushes 348 to 354, inclusive, to stationary terminals I in the plurality of banks 344; and causes the short circuiting of the winding of the starting relay 388 to thereby open its contacts and render the relay ineflective in the circuit. The pickup relay 484 also establishes a circuit from brush L3 conductor 4, left hand outer contact of relay 484, conductor 488, conductor 2 to brush 354 of the distributor switch 388; the pickup relay 484 also establishes another circuit from battery through the contact of release relay '485, conductor 4| 3, right hand outer contact of relay 484, conductor 4, the winding of a carry relay 5, conductor 445, brushes K3 and K4 to ground. The entire operation up to this point is a preliminary or preparatory function to start the multiplying operation at the proper place in the cycle.

The beginning of the actual multiplying operation occurs at rotative position 4 of the multiplying and control commutators when brush L3 makes contact and applies ground which will hereinafter be termed as the master grolmd. Ground is thereby established from brushes L4 and L3 through conductor 4| I, left hand outer contact of pickup relay 484, conductor 488, conductor H8 and the winding of a relay 411 to grounded battery.. The operation of relay 1 closes contacts to complete individual circuits from the units (U), tens (T), and hundreds (H), etc., columns in the multiplicand key bank 388 to their respective brushes 348 to 353 of the distributor switch 388. At the same time the master ground is supplied to the units column in the multiplier key bank 38| through brush 354, terminal 1 of its associated bank 344 and conductor 8. Contact9 in the units column of the multiplier key bank "I being closed due to the depression of that particular key, the master ground is continued through conductor 422 to a contact in each of the nine sets 383 of the multiplying commutator 385. This contact in each case as previously described is so cut that it is closed in the first half of the cycle, positions 1 to 14, inclusive, at a point representing the digit 

